Core Data, can't save context - ios

Question

I'm simply trying to save a ManagedObjectContext but while I get no errors, the fetched request returns the object with none of the saved values. Consider this simple example. You have a single object, you change a property and save it. The object is there but the property is not saved. As you can see, I want only one object, and the fetch returns this one object. BTW, the code is in a simple class, not the app delegate or a view controller.
Here is the sample code:
MyAppDelegate* delegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext* context = delegate.managedObjectContext;
NSEntityDescription *myEntityDesc = [NSEntityDescription entityForName:#"MyEntity" inManagedObjectContext:context];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:myEntityDesc];
NSError *error = nil;
NSArray *array = [context executeFetchRequest:request error:&error];
MyEntity* myEntity;
if (array == nil || [array count] < 1)
{
myEntity = [NSEntityDescription insertNewObjectForEntityForName:#"MyEntity" inManagedObjectContext:context];
}
else
{
myEntity = [array objectAtIndex:0];
}
myEntity.BoolValue = [NSNumber numberWithBool:someBoolValue];
myEntity.ID = #"Some ID";
if ([context save:&error])
{
NSLog(#"no error");
}
else
{
NSLog([NSString stringWithFormat:#"found core data error: %#", [error localizedDescription]]);
}
Here's the code used to retrieve the values later:
MyAppDelegate* delegate = [[UIApplication sharedApplication] delegate];
NSManagedObjectContext* context = delegate.managedObjectContext;
NSEntityDescription *MyEntityDesc = [NSEntityDescription entityForName:#"MyEntity" inManagedObjectContext:context];
NSFetchRequest *request = [[[NSFetchRequest alloc] init] autorelease];
[request setEntity:MyEntityDesc];
NSError *error = nil;
NSArray *array = [context executeFetchRequest:request error:&error];
MyEntity* myEntity;
if (array == nil || [array count] < 1)
{
//handle error
}
else
{
myEntity = [array objectAtIndex:0];
}
return [myEntity.BoolValue boolValue];

Answer 1

What does your NSManagedObject subclass look like? Since the fetch is working correctly (i.e. returning the entity), I suspect something is wrong in the subclass implementation.
You should declare a #property for each of the attributes on your data model. And in the implementation file, instead of using #synthesize you need to use #dynamic. Also make sure in your xcdatamodel that the entity has its class set, as well as the name.
#interface MyEntity : NSManagedObject
#property (nonatomic, strong) NSNumber * boolValue;
#end
#implementation MyEntity
#dynamic boolValue;
#end